Smoking, both in quantity and duration, increases the risk of recurrent Crohn's disease (CD) and the need for surgical treatment of CD. This study assessed awareness among patients with CD of the risks of smoking on their disease. We distributed self-administered questionnaires to 714 CD patients under follow-up at the University Hospital Birmingham, United Kingdom. We asked the patients eight multiple-choice (yes/uncertain/no) questions about the effects of smoking on health and on CD. We also determined relevant patient demographics, smoking history, and medical history. A total of 312 patients completed the questionnaire. Patients acknowledged the dangers of smoking on overall health (91.5%), lung cancer (89.6%), lung disease (90.8%), and cardiovascular disease (85.3%). Employed, educated, and homeowning patients demonstrated significantly more recognition of these smoking risks. Conversely, few patients recognized that smoking increases the risks of development of CD (9.5%) and of reoperation for CD (12.0%). Moreover, few patients recognized that both the quantity of cigarettes smoked (11.4%) and the duration of smoking (17.4%) increase the risk of reoperation. Patients with CD are unaware of the risks that smoking has on their disease, indicating a need for increased patient education with regard to the effects of smoking on CD.